Comparative Pharmacology
Head-to-head clinical analysis: CHOLAC versus HALFLYTELY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CHOLAC versus HALFLYTELY.
CHOLAC vs HALFLYTELY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lactulose is a synthetic disaccharide that is not absorbed in the small intestine. It is metabolized by colonic bacteria to short-chain fatty acids, primarily lactic acid and acetic acid, which lower the colonic pH. This acidification traps ammonia (NH3) as ammonium (NH4+) in the gut lumen, reducing serum ammonia levels. Additionally, the osmotic effect of lactulose draws water into the colon, producing a laxative effect.
PEG 3350 is an osmotic agent that causes water retention in the colon, leading to bowel evacuation. Electrolytes (sodium sulfate, potassium chloride, magnesium sulfate, sodium bicarbonate) prevent significant electrolyte shifts.
15-30 mL (10-20 g lactulose) orally once daily, titrated to produce 2-3 soft stools per day; maximum dose 60 mL/day. For hepatic encephalopathy: 30-45 mL (20-30 g) orally 3-4 times daily, titrated to 2-3 soft stools per day.
Oral: 1 liter (provided as powder for reconstitution) administered at a rate of 240 mL every 10 minutes until rectal effluent is clear or 4 liters total is consumed. Typically given as split-dose: half the volume the evening before and half the morning of colonoscopy.
None Documented
None Documented
0.5-1.5 hours for lactulose; active metabolites (e.g., acetic acid) have negligible systemic half-life due to rapid local metabolism.
Not applicable; PEG 3350 is not significantly absorbed and does not have a systemic half-life. The colon transit time is approximately 1 hour after ingestion.
Primarily fecal (biliary excretion of unchanged drug and metabolites); minimal renal excretion (<5%).
Primarily fecal elimination of unabsorbed PEG 3350; negligible systemic absorption <0.06%. Electrolytes are excreted renally and fecally.
Category C
Category C
Laxative
Laxative